U.S. patent number 6,585,059 [Application Number 09/882,055] was granted by the patent office on 2003-07-01 for motor grader blade retention system.
This patent grant is currently assigned to Caterpillar Inc.. Invention is credited to Donald R. Mast, David R. Michael, Jr., Wayne R. Tanner.
United States Patent |
6,585,059 |
Michael, Jr. , et
al. |
July 1, 2003 |
Motor grader blade retention system
Abstract
A mounting assembly for mounting a blade assembly to a motor
grader includes an upper and a lower retainer pivotally coupled
together. The upper and lower retainers are pivotable about a
single axis with respect to each other for grasping the blade
assembly therebetween.
Inventors: |
Michael, Jr.; David R. (Normal,
IL), Mast; Donald R. (Decatur, IL), Tanner; Wayne R.
(Chicago, IL) |
Assignee: |
Caterpillar Inc. (Peoria,
IL)
|
Family
ID: |
25379790 |
Appl.
No.: |
09/882,055 |
Filed: |
June 18, 2001 |
Current U.S.
Class: |
172/811 |
Current CPC
Class: |
E02F
3/7636 (20130101); E02F 3/815 (20130101) |
Current International
Class: |
E02F
3/76 (20060101); E02F 3/815 (20060101); E02F
003/76 () |
Field of
Search: |
;172/810,811,781 ;37/266
;248/229.13,229.23,228.4,230.4,231.51 |
References Cited
[Referenced By]
U.S. Patent Documents
Other References
Autoblade Tracer Grader, A Totally New Concept in Motorgrading, CMI
Corporation, No Date Given. .
Grader in Action, No date given..
|
Primary Examiner: Will; Thomas B.
Assistant Examiner: Florio; Kristine
Attorney, Agent or Firm: Sughrue Mion Zinn Macpeak
Claims
What is claimed is:
1. A mounting assembly for mounting a blade assembly to a motor
grader, comprising: an upper and a lower retainer pivotally coupled
together, at least one of said upper and lower retainer having a
arcuate cavity for retaining a wear strip therein, wherein said
upper and lower retainers are pivotable about a single axis with
respect to each other for grasping said blade assembly
therebetween.
2. The mounting assembly according to claim 1, wherein at least one
of said wear strips has a curved outer surface corresponding to an
inner surface of said circular cavity of each of said upper and
lower retainers.
3. The mounting assembly according to claim 2, wherein said curved
surface is provided along at least 1/2 of a periphery of each of
said wear strips.
4. The mounting assembly according to claim 1, wherein said
circular cavity has a crescent shape.
5. The mounting assembly according to claim 1, further including an
adjustment mechanism coupled to said upper and lower retainers for
facilitating rotation of said upper and lower retainers about said
single axis.
6. The mounting assembly according to claim 5, wherein said
adjustment mechanism includes an adjustment screw inserted through
a first and second adjustment block, wherein said first adjustment
block is coupled to said upper retainer and said second adjustment
block is coupled to said lower retainer, and wherein said
adjustment screw is rotated to cause said first and second
adjustment block to move with respect to each other, thereby
pivoting said upper and lower retainers with respect to each
other.
7. The mounting assembly according to claim 6, wherein said
adjustment screw is threadingly engaged with said first adjustment
block and said adjustment screw is slidingly engaged with said
second adjustment block, said adjustment mechanism further
including a flange extending from said adjustment screw so as to
abut said second adjustment block and a bracket detachably secured
to said second adjustment block.
Description
TECHNICAL FIELD
The present invention relates generally to a motor grader, and more
particularly, to an apparatus and method for retaining a grader
blade.
BACKGROUND
Motor graders are typically used to perform displacement,
distribution and leveling of material, such as soil. Generally, a
motor grader includes a tractor unit coupled to a grader group via
a tow bar assembly. The grader group includes a blade assembly
having a grader blade, as well as a mounting assembly having a
support bracket with retainers extending therefrom. The blade
assembly is positioned in the retainers such that the grader blade
is supported by the support bracket. Wear strips are provided
between the retainers and the blade assembly to facilitate the
retention of the grader blade in the assembly, while allowing
sliding movement of the blade assembly with respect to the
retainers. The tractor unit moves the blade assembly over the
ground, so that the grader blade engages with the material, such as
soil, so as to displace, distribute or level the soil.
During use of the motor grader, the grader blade is tipped and
sideshifted, to manipulate the material as discussed above. The
wear strips tend to erode during use, thus loosening the retention
of the grader blade so that there is unintended motion between the
grader blade and support bracket. A loose grader blade inhibits the
accurate displacement, distribution and leveling of the
material.
To overcome this problem, shims are installed to fill any
horizontal gaps caused by the erosion of the wear strips. However,
using shims is work intensive, and thus increases the maintenance
cost of the motor grader. Moreover, the insertion of shims only
inhibits, and does not effectively stop, the unintended motion
between the grader blade and the support bracket.
U.S. Pat. No. 5,687,800 provides a retaining apparatus in which the
necessity of shims is reduced. In particular, a retaining apparatus
having a turnbuckle mechanism facilitates the tightening of the fit
between the retainers and the blade assembly as the wear strips
erode. However, the turnbuckle mechanism is complex. In addition,
the turnbuckle mechanism only allows for a limited movement of the
retainers with respect to each other, and thus, the method for
assembling the blade assembly to the mounting assembly is
cumbersome because the blade assembly must be slid sideways into
the retainers. Also, the wear strips must be aligned between the
retainer and the blade assembly. The present invention is intended
to overcome these and other problems of conventional motor grader
retention systems, by providing a retaining system in which the
mechanism for adjusting the fit of the retainers is simple, the
wear strips are self-aligning, and the method for assembling the
blade assembly to the mounting assembly is efficient.
SUMMARY OF THE INVENTION
According to a first aspect of the invention, a mounting assembly
for mounting a blade assembly to a motor grader, is provided with
an upper and lower retainer pivotally coupled together, wherein the
upper and lower retainers are pivotable about a single axis with
respect to each other for grasping the blade assembly
therebetween.
According to a second aspect of the invention, a wear strip for
mounting a blade assembly to a mounting assembly of a motor grader
includes a member having a flat inner surface and a curved outer
surface, wherein the curved outer surface mates with the mounting
assembly and the flat inner surface mates with the blade
assembly.
According to a third aspect of the invention, a method for
assembling a mounting assembly to upper and lower blade rails of a
blade assembly is provided. The mounting assembly includes upper
and lower retainers pivotally coupled together, and self-aligning
wear strips. The method includes the steps of pivoting the upper
and lower retainers away from each other, placing the upper
retainer over the upper blade rail and placing the lower retainer
under the lower blade rail, and pivoting the upper and lower
retainers toward each other until the upper and lower blade rails
are securely fitted to the upper and lower retainers with the
self-aligning wear strips disposed therebetween.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be more fully understood from the following
detailed description of the preferred embodiments, taken in
connection with the accompanying drawings, in which:
FIG. 1 is a perspective view of the grader group having the
mounting assembly coupled to the blade assembly;
FIG. 2 is a side view of the mounting assembly coupled to the blade
assembly;
FIG. 3 is an exploded view of the mounting assembly;
FIG. 4 is a side view of the mounting assembly in an open position
for receiving the blade assembly; and
FIG. 5 is an enlarged view of the adjustment mechanism.
DETAILED DESCRIPTION
A preferred embodiment of the invention will now be described in
reference to the accompanying drawings.
Referring to FIG. 1, a grader group 101 for a motor grader is
shown. The grader group 101 includes a mounting assembly 100 and a
blade assembly 150. The mounting assembly 100 supports the blade
assembly 150 on the motor grader. In addition, a circle assembly
210 supports the mounting assembly 100 to the motor grader.
The grader group 101 is pivotable up and down with respect to the
circle assembly 210. The blade assembly 150 is slidable
side-to-side with respect to the mounting assembly 100, and is
rotatable with respect to the circle assembly 210. The combination
of these motions allow the blade assembly 150 to displace,
distribute and level a material as desired by the operator of the
motor grader.
The mounting assembly 100 includes (see FIG. 2) a first upper
retainer 110, a second upper retainer 111, a first lower retainer
120, a second lower retainer 121, a first upper wear strip 130, a
second upper wear strip 131, a first lower wear strip 135, a second
lower wear strip 136, a first retainer pin 140, a second retainer
pin 141, and first and second adjustment mechanisms 170, 172.
The circle assembly 210 includes a circle member 215, a first
support arm 212 and a second support arm 214. The first support arm
212 and the second support arm 214 are secured to the circle member
215. The first support arm 212 is pivotally mounted to the first
upper retainer 110 via the first retainer pin 140. The second
support arm 214 is pivotally mounted to the second upper retainer
111 via the second retainer pin 141.
The first upper retainer 110 and the first lower retainer 120 are
pivotally coupled to each other via the first retainer pin 140. The
first upper retainer 110 and the first lower retainer 120,
therefore, are pivotable about a single axis X which corresponds
with the longitudinal axis of the first retainer pin 140 when the
retainers 110, 120 and pin 140 are assembled (see FIG. 3). The
second upper retainer 111 and the second lower retainer 121 are
arranged to be pivotally coupled in the same general manner.
The first upper retainer 110 includes a first upper cylindrical
cavity 115 in which the first upper wear strip 130 is disposed. The
first lower retainer 120 includes a first lower cylindrical cavity
125 in which the first lower wear strip 135 is disposed. Similarly,
the second upper retainer 111 has a second upper cylindrical cavity
116, and the second lower retainer 121 has a second lower
cylindrical cavity 126 for receiving the second upper and lower
wear strips 131, 136, respectively.
The cylindrical cavities 115, 116, 120, 121 may be formed in a
half-moon shape, crescent shape, or similar shape wherein a rounded
inner surface that defines the cavity generally corresponds to the
shape of a portion of the outer surface of the associated wear
strip placed therein.
The first upper wear strip 130, for example, has a curved outer
surface 130a and a flat inner surface 130b (see FIG. 3). The curved
outer surface 130a corresponds in shape to the inner surface of the
first upper cylindrical cavity 115. Each of the wear strips 130,
131, 135, 136 may include this structure of a curved outer surface
and a flat inner surface, wherein the curved outer surface
facilitates the self-aligning feature of the present invention, as
discussed in greater detail below.
The blade assembly 150 includes a moldboard 190, an upper blade
rail 160 and a lower blade rail 165, and a grader blade 155. The
grader blade 155 is attached to a first side, or front, of the
moldboard 190 and the upper and lower blade rails 160, 165 are
attached to a second side, or rear, of the moldboard 190.
The upper blade rail 160 is retained to the mounting assembly 100
so that the upper wear strips 130, 131 are respectively disposed
between the upper blade rail 160 and the upper retainers 110, 111.
Similarly, the lower blade rail 165 is retained to the mounting
assembly 100 so that the lower wear strips 135, 136 are
respectively disposed between the lower blade rail 165 and the
lower retainers 120, 121.
The circle assembly 210 also includes a tip support member 222 for
supporting a tip cylinder 220 thereto. The tip cylinder 220 is
secured to a support bracket 230 of the mounting assembly 100.
A side shift cylinder assembly 250 (see FIG. 1) is provided for
shifting the grader blade 155 side-to-side with respect to the
mounting assembly 100. The cylinder assembly 250 includes a
cylinder portion 251 that is attached to the second upper retainer
111, and a piston portion 252 that is connected to the upper and
lower blade rails 160, 165 via a cylinder mount 253. Actuation of
the cylinder assembly 252 causes the upper and lower blade rails
160, 165 to slide with respect to the second upper retainer 111,
and therefore, the mounting assembly 100. Thus, the upper and lower
blade rails 160, 165 slide with respect to the wear strips 130,
135, 131, 136.
Each of the first and second upper retainers 110, 111 includes
first and second upper U-shaped retaining members 330, 331,
respectively. Each of the first and second lower retainers 120, 121
includes first and second lower U-shaped retaining members 335,
336. In the embodiment illustrated in FIG. 3, the first and second
lower retainers 120, 121 fit between the U-shaped retaining members
330, 331 of the first and second upper retainers 110, 111,
respectively, and are pivotally held by pins 140, 141,
respectively. Of course, it should be understood that the first and
second upper retainers 110, 111 could alternatively fit within the
U-shaped retaining members 335, 336 of the first and second lower
retainers 120, 121.
The first upper retainer 110 has first upper retainer pin holes 340
and the first lower retainer 120 has first lower retainer pin holes
342. Additionally, the first support arm 212 has a first support
arm retainer pin hole 348. The first retainer pin 140 fits within
the first upper and lower retainer pin holes 340, 342 and the first
support arm retainer pin hole 348 to pivotally connect the first
upper retainer 110 to the first lower retainer 120.
Similarly, although hidden from view in the Figures, the second
upper retainer 111 has second upper retainer pin holes and the
second lower retainer 121 has second lower retainer pin holes.
Additionally, the second support arm 214 has a second support arm
retainer pin hole. The second retainer pin 141 fits within the
second upper and lower retainer pin holes and the second support
arm retainer pin hole as described above with respect to the first
upper and lower retainer 110, 120 assembly. Hence, the second upper
retainer 111 is pivotal with respect to the second lower retainer
121.
The first adjustment mechanism 170 is shown in detail in FIGS. 3
and 5. Although the second adjustment mechanism 172 is not
described in detail, its structure is similar to the first
adjustment mechanism 170. The first and second adjustment
mechanisms 170, 172 allow for the upper and lower retainers to be
pivoted with respect to each other, as discussed in detail
below.
The first adjustment mechanism 170 includes a first adjustment
screw 310 threadingly engaged with a first upper adjustment block
312. The first adjustment screw 310 is also engaged with a first
lower adjustment block 313, however, it is slidingly engaged and
not threaded thereto. The first upper adjustment block 312 is
coupled to the first upper retainer 110 by a first upper retainer
pin (not shown) received in a first upper adjustment pin hole 316
of the first upper adjustment block 312. The first lower adjustment
block 313 is coupled to the first lower retainer 120 by a first
lower adjustment pin 317 received in first lower retainer pin holes
323 of the first lower retainer 120.
In addition, one end of the first adjustment screw 310 may be
provided with a first hex head 320 for facilitating rotation of the
first adjustment screw 310 with a tool, such as a socket
wrench.
A flange 520 is fixed to the first adjustment screw 310 so as to
abut against one side of the first lower adjustment block 313. A
bracket 510 is detachably connected to the adjustment mechanism
170. In particular, the bracket 510 is secured to the first lower
adjustment block 313 by a bolt or other similar device so as to be
removable from the first lower adjustment block 313. The operation
of the first adjustment mechanism 170 is described in greater
detail below.
To the extent possible, FIG. 1 shows the second adjustment
mechanism 172. As shown, a second hex head 321 is provided at the
end of a second adjustment screw 311. Although the second upper and
lower adjustment blocks, the second upper and lower adjustment
pins, and the second upper and lower retainer adjustment pin holes
are hidden from view, these elements are understood to have a
similar structure to the first adjustment mechanism.
INDUSTRIAL APPLICABILITY
In order to attach the blade assembly 150 to the mounting assembly
100, the first and second adjustment mechanisms 170, 172 cause the
upper and lower retainers 110, 111, 120, 121 to pivot about the
retainer pivot pins' 140, 141 axes so that the cylindrical cavities
115, 116, 125, 126 move away from each other, respectively. The
blade assembly 150 is then inserted within an opening between the
upper and lower retainers 110, 111, 120, 121, and then the first
and second adjustment mechanisms 170, 172 cause the upper and lower
retainers 110, 111, 120, 121 to move toward each other. This
process will now be described in further detail, with respect to
the first upper and lower retainers.
Referring to FIG. 4, the first upper and lower retainers 110, 120
are shown. The first upper and lower retainers 110, 120 pivot about
the pivot pin 140, in a scissor-like fashion. In other words, the
first upper and lower retainers 110, 120 together form a jaw which
opens and closes as indicated by the arrows A, B, to allow for the
insertion of the blade rails 160, 165 of the blade assembly
150.
The first adjustment screw 310 is rotated to cause the first upper
and lower retainers 110, 120 to pivot. The first adjustment screw
310 is rotatable in a first direction to cause the jaw to open, and
in a second direction to cause the jaw to close. In particular, as
the first adjustment screw 310 rotates, the first upper and lower
adjustment blocks 312, 313 move with respect to each other thereby
causing the first upper and lower retainers 110, 120 to pivot with
respect to each other.
FIG. 5 illustrates the bracket 510 in a locked position, wherein
the hex head 320 is prevented from accidentally rotating due to
vibrations, etc. In particular, a second end 510b partially covers
the hex head 320 so that it cannot unintentionally rotate. In order
to operate the first adjustment mechanism 170, the bracket 510 is
removed and then flipped and replaced so that the first end 510a
fits over the flange 520. This secures the flange 520 to the first
lower adjustment block 313 via the bracket 520. This position also
frees the hex head 320 to rotate.
As the first adjustment screw 310 rotates, it causes the first
upper and lower adjustment blocks 312, 313 to move closer together
(or farther apart depending on the rotation direction of the first
adjustment screw 310) due to the threaded engagement of the first
adjustment screw 310 with the first upper adjustment block 312. As
the first adjustment screw 310 rotates, the first upper adjustment
block 312 moves along the length of the first adjustment screw 310
due to their threaded engagement. Thus, the first upper adjustment
block 312 is caused to move closer to, or further from, the first
lower adjustment block 313 since the first lower adjustment block
313 is fitted against the flange 520 by the first end 510a.
As the first upper and lower adjustment blocks 312, 313 move closer
together, the upper and lower retainers 110, 120 pivot about the
single axis X due to the engagement of the first upper adjustment
pin hole 316 to the first upper adjustment pin of the first upper
retainer 110, and the respective engagement of the first lower
adjustment pin 317 to the first lower adjustment pin hole 323 of
the first lower retainer 120.
The upper and lower blade rails 160, 165 are then placed in
position so that as the jaw of the upper and lower retainers 110,
120 closes, the upper and lower blade rails 160, 165 will be
retained therein with the first upper and lower wear strips 130,
135 disposed therebetween. As the first adjustment screw 310 is
further rotated, the jaw of the upper and lower retainers 110, 120
tightens against the upper and lower blade rails 160, 165 so that
the first upper and lower wear strips 130, 135 are securely held
therein, thereby completing the attachment of the mounting and
blade assemblies 100, 150.
Thus, the cumbersome process of sliding the blade assembly 150 into
the side of mounting assembly 100 is eliminated, and instead, the
blade assembly 150 can be easily and directly placed into the
retainers of the mounting assembly 100 so as to be grasped by the
mounting assembly 100.
The curved shape of the first upper and lower wear strips 130, 135
facilitate the self-alignment of the wear strips 130, 135 within
the first upper and lower cylindrical cavities 115, 125 as the
first upper and lower retainers 110, 120 tighten against the upper
and lower blade rails 160, 165. Thus, the wear strips 130, 135 do
not have to be additionally manipulated into alignment when the
blade assembly 150 is secured to the mounting assembly 100; the
wear strips 130, 135 automatically self-align as the assemblies are
secured together.
The shape of the first upper and lower wear strips 130, 135 is not
limited to that illustrated in the Figures. A semi-cylindrical
surface is shown in the Figures, but the curved surface may be
smaller or larger than a half-circle. The curved surface may be
more or less than 1/2 the periphery of the wear strip.
As the first upper and lower wear strips 130, 135 erode over a
period of extended use of the blade assembly 150, the first
adjustment screw 310 can be further tightened to remove any gaps
that form due to this erosion. Due to the curved surfaces of the
first upper and lower wear strips 130, 135, the wear strips 130,
135 tend to self-align as the first adjustment screw 310 is
tightened. Thus, the use of shims is avoided without requiring a
complicated structure for filling the gaps of the wear strips.
After the blade assembly 150 is properly mounted to the mounting
assembly 100, the bracket 510 may be repositioned so that the hex
head 320 is once again locked into position by the second end 510b.
This locking position prevents the adjustment screw 310 from
unintentionally rotating due to vibrations, etc. Thus, the blade
rails 160, 165 are prevented from unintentionally loosening with
respect to the first upper and lower retainers 110, 120.
The above description is directed to the first upper and lower
retainers 110, 120, first upper and lower wear strips 130, 135,
first adjustment mechanism 170, and their associated components.
The second upper and lower retainers 111, 121, second upper and
lower wear strips 131, 136, and the second adjustment mechanism 172
are operated in the same manner as that discussed above.
Shown and described are several preferred embodiments of the
invention, though it will be apparent to those skilled in the art
that many changes and modifications may be made without departing
from the invention in its broader aspects. For instance, a third
upper and lower retainer may be provided, or only a single upper
and lower retainer may be provided, for engaging with the blade
rails 160, 165. Therefore it is intended that the appended claims
cover all such changes and modifications as fall within the true
spirit and scope of the invention.
* * * * *